英语语法：190 Like Versus As（在线收听）

Grammar Girl here.

Today's topic is like versus as.

Now the very attentive listeners will notice a difference between that ad and what I said last week, and that difference is the reason today's topic is like versus as. This week, I said, “I just enter two passwords, and it's as if I'm sitting at my own computer.” Last week, I said, “I just enter two passwords, and it's like I'm sitting at my own computer,” and by saying that I unwittingly stumbled into a raging grammar war.

The background is that traditionally like is a preposition and as is a conjunction. Nevertheless, people have been using like as if it were a conjunction (as I did) for at least 100 years, and grammarians have been raging against that use for just as long. In fact, the Harper Dictionary of Contemporary Usage states that “probably no single question of usage has created greater controversy in recent years” than the conjunctive use of like.

First of all, let’s quickly review what a preposition is, and what a conjunction is. According to the book Woe Is I, a preposition is “a word that ‘positions’ or situates words in relation to one another.”  Examples are in, around, and through. A conjunction is, simply, “a connecting word.” Common conjunctions are and, but, and or (1).

The proper way to differentiate between like and as is to use like when no verb follows (2). For example, Squiggly throws like a raccoon or It acted just like my computer. Notice that when I use like, the words that come after are generally simple. A raccoon and my computer are the objects of the preposition.

If the clause that comes next includes a verb, then you should use as. For example, Squiggly throws as if he were a raccoon or It acted just as I would expect my computer to behave. Notice that when I use as, the words that come after tend to be more complex.

You generally hear like used in everyday speech, so that helps me remember that like is the simpler word—or at least it is followed by simpler words. As sounds stuffier and is followed by a more complex clause that contains a verb.

Whether you abide by this rule or not probably depends on how much of a grammar stickler you are. It's common to hear sentences like this: It's like I'm sitting at my own computer. And as a result, many people don't know it's wrong. In one survey, 21 percent of professional writers and editors said they found such constructions acceptable in casual speech. On the other hand, only 6 percent thought the construction would be OK in formal writing (3).

I have to admit that after reading entries in three usage guides (3,4,5), I felt a bit brow beaten about the whole topic. Even as like is becoming more entrenched in everyday use, professional grammarians are absolutely resolved that this is a trend worth fighting. Many language experts seem fully prepared to rail against it with all their might, and some of the comments were quite vicious.

So my advice is don't do it—don't use like as a conjunction, especially in writing, unless you are ready for the full force of rampaging grammarians to rain down on you (which is not what I'm generally going for in the advice I give you).

Here are more examples of correct sentences to help you remember the rule:

EXAMPLE: My cousin looks like Batman.
EXAMPLE: My neighbor yelled like a maniac.

EXAMPLE: It's as if my cousin were Batman.
EXAMPLE: My neighbor yelled as though he were a maniac.

A final note is that there is no discernible difference between as if and as though. Some sources say that as if is often used for less likely scenarios—my cousin being Batman—and as though for more likely scenarios—my neighbor is a maniac—but this isn't a definitive rule.

That's all.

This week's book winners are Angie, Jennifer, and Ken. They've all won a copy of my new audiobook, Grammar Girl's Quick and Dirty Tips to Clean Up Your Writing, which is a one-hour downloadable audiobook covering 24 different topics. You can buy the book for only $4.95 at iTunes and Audible.com.